Harman Kardon HKTS 200SUB
amplifier board — fixed.
The Harman Kardon HKTS 200SUB — and the wider HKTS 9/11/16/20/30/60 family, which all ship the same subwoofer amplifier hardware — is known for one signature failure: the standby light flashes continuously and the subwoofer refuses to wake up. The cause sits on the power supply board around a single rectifier diode, and the fix does not require replacing the whole unit.
Is it really the board?
These are the failure patterns we see on the Harman Kardon HKTS 200SUB. Match your symptom before spending a cent.
- Power LED blinking continuously, sub never turns onBOARD — WE FIX THIS
The most common HKTS failure. A Schottky rectifier diode on the power supply (feeding the low-voltage logic rail) degrades with heat and age; the supply can no longer hold a stable rail, so the protection logic sees a fault, resets, and tries again — blink, retry, blink, forever.
- Stuck in standby, ignores the audio signal entirelyBOARD — WE FIX THIS
The same rectifier and its associated filter capacitors have degraded enough that the standby/auto-sense logic can't reach a stable "ready" state, so the sub never wakes even when it detects a signal.
- Auto-on works and the LED looks normal, but there is zero bass outputBOARD — WE FIX THIS
The power supply can still maintain the low-current standby rail well enough to run the auto-sense logic, but not the higher-current rail the amplifier stage needs — so the sub appears to power on normally but never actually produces sound.
- Audible hum or buzz from the subwooferUSUALLY A CABLING ISSUE
Most HKTS hum complaints trace back to a loose or oxidized RCA/LFE input connection or a ground-potential mismatch with the receiver, not a board fault. Clean the input jack and try the Normal (not LFE) input mode before assuming electronics.
- Amplifier board visibly burnt or blackenedSEND PHOTOS FIRST
A small number of units show visible charring on the amplifier board from sustained heavy use in a sealed enclosure. Send us photos before shipping — this is usually still repairable, but we'll confirm before you pay for shipping.
Why the original board fails
Every model in the HKTS satellite-system family — from the compact HKTS 9 up through the HKTS 30 — ships the same subwoofer amplifier and power supply hardware. That power supply centers on a Schottky rectifier diode feeding the logic rail, backed by a toroidal transformer and several electrolytic filter capacitors. Years of standby heat degrade the rectifier and let the filter capacitors dry out; the rail sags right as the unit tries to wake from standby, the protection logic reads that sag as a fault, and it resets — which is exactly the blinking-light pattern that has its own thread on every AV forum. In milder cases the rail holds up just enough to run the low-current auto-sense logic but not the amplifier stage, so the sub looks like it powered on but stays silent.
Because the fault is concentrated in a handful of aging components around one rectifier, mail-in repair is quick and economical for this model, and repaired units hold up well. High repair demand for the HKTS family is exactly the signal we use to justify tooling a plug-and-play replacement board for it.
Mail-in repair for this model
No standardized board yet — but our bench repairs these at component level, tested and shipped back.
- 01 Submit the repair form with your symptoms and photos
- 02 We confirm it's repairable and send our address — you ship just the board
- 03 Bench diagnosis, firm quote by email — no fix, no fee
- 04 Repaired, tested, shipped back — return shipping on us
Questions owners ask
Is the blinking light always the power supply?
In the large majority of HKTS cases, yes — a degraded rectifier diode and aging filter capacitors on the power supply board. Diagnosis at our bench confirms it before any repair is quoted.
Can I send only the internal board?
Yes. The rear plate comes out with a screwdriver and the connectors unplug by hand. Shipping the plate alone is much cheaper than shipping the whole cabinet.
My satellites work fine — only the sub is dead. Normal?
Completely normal. The satellites are passive and powered by the receiver; the subwoofer has its own internal amplifier and power supply, which is the part that fails.
Does this apply to my HKTS 16 / HKTS 30 / other HKTS model, not just the 200SUB?
Yes — Harman Kardon used the same subwoofer amplifier hardware across the whole HKTS family (9, 11, 16, 20, 30, 60 and the 200/210/220SUB variants). If your model number is different but starts with HKTS, this is very likely the same board.